package gagak.framework.web.io;


import gagak.framework.web.utils.Assert;
import gagak.framework.web.utils.StringUtils;

import java.io.*;
import java.net.URI;
import java.net.URL;
import java.nio.channels.FileChannel;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.WritableByteChannel;


/*
 *
 */
public class FileSystemResource extends AbstractResource implements WritableResource {

    private final File file;

    private final String path;


    public FileSystemResource(File file) {
        Assert.notNull(file, "File must not be null");
        this.file = file;
        this.path = StringUtils.cleanPath(file.getPath());
    }

    /*
     * Create a new {@code FileSystemResource} from a file path.
     * <p>Note: When building relative resources via {@link #createRelative},
     * it makes a difference whether the specified resource base path here
     * ends with a slash or not. In the case of "C:/dir1/", relative paths
     * will be built underneath that root: e.g. relative path "dir2" ->
     * "C:/dir1/dir2". In the case of "C:/dir1", relative paths will apply
     * at the same directory level: relative path "dir2" -> "C:/dir2".
     *
     * @param path a file path
     */
    public FileSystemResource(String path) {
        Assert.notNull(path, "Path must not be null");
        this.file = new File(path);
        this.path = StringUtils.cleanPath(path);
    }


    /*
     * Return the file path for this resource.
     */
    public final String getPath() {
        return this.path;
    }

    /*
     * This implementation returns whether the underlying file exists.
     *
     * @see File#exists()
     */
    @Override
    public boolean exists() {
        return this.file.exists();
    }

    /*
     * This implementation checks whether the underlying file is marked as readable
     * (and corresponds to an actual file with content, not to a directory).
     *
     * @see File#canRead()
     * @see File#isDirectory()
     */
    @Override
    public boolean isReadable() {
        return (this.file.canRead() && !this.file.isDirectory());
    }

    /*
     * This implementation opens a NIO file stream for the underlying file.
     *
     * @see java.io.FileInputStream
     */
    @Override
    public InputStream getInputStream() throws IOException {

        return  new FileInputStream(this.file);
       /* try {
            return Files.newInputStream(this.file.toPath());
        } catch (NoSuchFileException ex) {
            throw new FileNotFoundException(ex.getMessage());
        }*/
    }

    /*
     * This implementation checks whether the underlying file is marked as writable
     * (and corresponds to an actual file with content, not to a directory).
     *
     * @see File#canWrite()
     * @see File#isDirectory()
     */
    @Override
    public boolean isWritable() {
        return (this.file.canWrite() && !this.file.isDirectory());
    }

    /*
     * This implementation opens a FileOutputStream for the underlying file.
     *
     * @see java.io.FileOutputStream
     */
    @Override
    public OutputStream getOutputStream() throws IOException {

        return  new FileOutputStream(this.file);
       // return Files.newOutputStream(this.file.toPath());
    }

    /*
     * This implementation returns a URL for the underlying file.
     *
     * @see File#toURI()
     */
    @Override
    public URL getURL() throws IOException {
        return this.file.toURI().toURL();
    }

    /*
     * This implementation returns a URI for the underlying file.
     *
     * @see File#toURI()
     */
    @Override
    public URI getURI() throws IOException {
        return this.file.toURI();
    }

    /*
     * This implementation always indicates a file.
     */
    @Override
    public boolean isFile() {
        return true;
    }

    /*
     * This implementation returns the underlying File reference.
     */
    @Override
    public File getFile() {
        return this.file;
    }

    /*
     * This implementation opens a FileChannel for the underlying file.
     *
     * @see FileChannel
     */
    @Override
    public ReadableByteChannel readableChannel() throws IOException {

        return null;
      /*  try {
            return FileChannel.open(this.file.toPath(), StandardOpenOption.READ);
        } catch (NoSuchFileException ex) {
            throw new FileNotFoundException(ex.getMessage());
        }*/
    }

    /*
     * This implementation opens a FileChannel for the underlying file.
     *
     * @see FileChannel
     */
    @Override
    public WritableByteChannel writableChannel() throws IOException {
        return null;
        //return FileChannel.open(this.file.toPath(), StandardOpenOption.WRITE);
    }

    /*
     * This implementation returns the underlying File's length.
     */
    @Override
    public long contentLength() throws IOException {
        return this.file.length();
    }


    @Override
    public Resource createRelative(String relativePath) {
        String pathToUse = StringUtils.applyRelativePath(this.path, relativePath);
        return new FileSystemResource(pathToUse);
    }

    /*
     * This implementation returns the name of the file.
     *
     * @see File#getName()
     */
    @Override
    public String getFilename() {
        return this.file.getName();
    }

    /*
     * This implementation returns a description that includes the absolute
     * path of the file.
     *
     * @see File#getAbsolutePath()
     */
    @Override
    public String getDescription() {
        return "file [" + this.file.getAbsolutePath() + "]";
    }


    @Override
    public boolean equals(Object other) {
        return (this == other || (other instanceof FileSystemResource &&
                this.path.equals(((FileSystemResource) other).path)));
    }


    @Override
    public int hashCode() {
        return this.path.hashCode();
    }

}
